NASA’s Parker Solar Probe has been in studying the Sun for the last six years. In 2021 it was hit directly by a coronal mass ejection when it was a mere 10 million kilometres from the solar surface. Luckily it was gathering data and images enabling scientists to piece together an amazing video. The interactions between the solar wind and the coronal mass ejection were measured giving an unprecedented view of the solar corona.
The Sun is a fascinating object and as our local star, has been the subject of many studies. There are still mysteries though and it was hoping to unravel some of these that the NASA Parker Solar Probe was launched. It was sent on its way by the Delta IV heavy back in 2018 and has flown seven times closer to the Sun than any spacecraft before it.
Illustration of the Parker Solar Probe spacecraft approaching the Sun. Credits: Johns Hopkins University Applied Physics LaboratoryBy the time Parker completes its seven year mission it will have completed 24 orbits of the Sun and flown to within 6.2 million kilometres to the visible surface. For this to happen, its going to get very hot so the probe has a 11.4cm thick carbon composite shield to keep its components as cool as possible in the searing 1,377 Celsius temperatures.
Flying within the Sun’s outer atmosphere, the corona, the probe picked up turbulence inside a coronal mass ejection as it interacted with the solar wind. These events are eruptions of large amounts of highly magnetised and energetic plasma from within the Sun’s corona. When directed toward Earth they can cause magnetic and radio disruptions in many ways from communications to power systems.
Image of a coronal mass ejection being discharged from the Sun. (Credit: NASA/Goddard Space Flight Center/Solar Dynamics Observatory)Using the Wide Field Imager for Parker Solar Probe (WISPR) and its prime position inside the solar atmosphere, unprecedented footage was captured (click on this link for the video). The science team from the US Naval Research Laboratory revealed what seemed like turbulent eddies, so called Kelvin-Helmholtz instabilities (KHIs) in one of the images. Turbulent eddy structures like these have been seen in the atmosphere of terrestrial planets. Strong wind shear between upper and lower cloud levels causes thin trains of crescent wave like clouds.
Member of the WISPR team Evangelos Paouris PhD was the eagle eyed individual that spotted the disturbance. Paouris and team analysed the structure to verify the waves. The discovery of these rare features in the CME have opened up a whole new field of investigations.
The KHIs are the result of turbulence which plays a key role in the movement of CMEs as they flow through the ambient solar wind. Understanding the CMEs and their dynamics of CMEs and a more fuller understanding of the Sun’s corona. This doesn’t just help us understand the Sun but also helps to understand the effect of CMEs on Earth and our space based technology.
Source : WISPR Team Images Turbulence within Solar Transients for the First Time
